Field of the Invention
The invention relates to a projection screen.
Description of Related Art
Projection screen is widely used in daily life. For example, the projection screen is applied in educational institutions, command centers, conference rooms or exhibition centers, etc. An image beam projected by an external image source (for example, a projector) is adapted to be projected onto the projection screen, and image information carried by the image beam can be imaged on the projection screen to facilitate a user presenting expressing content to public through the projection screen. Therefore, the projection screen plays an important role in information transmission.
On the other hand, as electronic apparatuses are developed toward a trend of multifunction, a conventional button-type operation interface has been gradually unable to meet the needs of users. In this case, a touch technique is quickly developed. Compared with the conventional button-type operation interface, an input method of a touch operation interface is more convenient and intuitive, and a user can directly perform a touch input operation on a display surface of the electronic apparatus by using a finger or a stylus. Besides that the touch technique is applied to the display surface of the electronic apparatus, it can also be applied to a projection screen, such that the user can intuitively perform the touch input operation on the projection screen.
However, the conventional projection screen usually has following problems: in the conventional projection screen, optical microstructures thereon are generally exposed, and in case of impact of a foreign object or when the projection screen is retracted, the optical microstructures on the projection screen are liable to be damaged, which may cause a poor appearance of the projection screen or aggravate optical quality of a projected image. Moreover, the projection screen is liable to be contaminated by foreign matters (for example, suspended particles) adhered on the optical microstructures. When the projection screen is cleaned, it is liable to damage the optical microstructures of the projection screen. Therefore, the conventional projection screen has poor reliability.
On the other hand, in the conventional projection screen, the optical microstructures are arranged unidirectionally. When the user executes a touch operation on the conventional projection screen, the stylus or the finger cannot move smoothly in all directions. Meanwhile, the stylus or the finger is also liable to cause a damage of the optical microstructures.
Moreover, when a scattering capability of the projection screen itself is insufficient, the image beam is liable to be reflected towards a specific direction (for example, a reflection direction of the image beam). Therefore, when the user views the projection screen from certain viewing angles (for example, a reflection angle of the image beam), the user may feel that the image is over bright, and such phenomenon is the so-called “hot spot” phenomenon. Comparatively, when the user views the projection screen from other viewing angles, the user may feel that the image is over dark. In other words, under different viewing angles, the image may have different brightness, i.e. the projection screen has a phenomenon of uneven brightness. It is known that the hot spot phenomenon and the phenomenon of uneven brightness may all cause poor imaging quality of the image.
Therefore, how to resolve the above problem becomes a current focus of research and development for R&D personnel of the field.
The information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the Background section does not mean that one or more problems to be resolved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art.